Circuitry for a plurality of induction elements for an aerosol generating device

Abstract

Circuitry for a plurality of induction elements for an aerosol generating device is disclosed. Each of the plurality of induction elements is for inductive heating of one or more susceptors for heating aerosol generating material in use. The circuitry includes a plurality of driver arrangements, each one of the plurality of driver arrangements being arranged to provide, from an input direct current, an alternating current to a respective one of the plurality of induction elements in use. Each driver arrangement includes one or more first transistors each controllable by a switching potential to substantially allow current to pass therethrough in use. The circuitry also includes a converter arranged to step up an input potential to provide the switching potential in use, the converter being common to each of the plurality of driver arrangements.

The invention claimed is: 
     
       1. Circuitry for a plurality of induction elements for an aerosol generating device, the plurality of induction elements being for inductive heating of one or more susceptors for heating aerosol generating material in use, the circuitry comprising:
 a plurality of driver arrangements, each one of the plurality of driver arrangements being arranged to provide, from an input direct current, an alternating current to a respective one of the plurality of induction elements in use, each of the plurality of driver arrangements comprising one or more first transistors each controllable by a switching potential to substantially allow current to pass therethrough in use, wherein one or more of the plurality of driver arrangements comprises a plurality of transistors arranged in an H-bridge configuration, one or more of the plurality of transistors is one of the one or more first transistors, the H-bridge configuration comprises a high side pair of transistors and a low side pair of transistors, the high side pair of transistors being for connection to a first electric potential higher than a second electric potential to which the low side pair of transistors is for connection is use, and one or both of the high side pair of transistors is one of the one or more first transistors; and 
 a converter arranged to step up an input potential to provide the switching potential in use, the converter being common to each of the plurality of driver arrangements. 
 
     
     
       2. The circuitry according to  claim 1 , wherein the converter is arranged such that in use the switching potential is higher than the first electric potential. 
     
     
       3. The circuitry according to  claim 1 , wherein one or both of the low side pair of transistors is one of the one or more first transistors. 
     
     
       4. The circuitry according to  claim 1 , wherein each of the plurality of driver arrangements is arranged for connection of a DC power source in use across a first point between the high side pair of transistors and a second point between the low side pair of transistors. 
     
     
       5. The circuitry according to  claim 1 , wherein each of the plurality of driver arrangements is arranged for connection of the respective one of the plurality of induction elements in use across a third point between one of the high side pair of transistors and one of the low side pair of transistors and a fourth point between the other of the high side pair of transistors and the other of low side second pair of transistors. 
     
     
       6. The circuitry according to  claim 1 , wherein each of the one or more first transistors is arranged such that, when the switching potential is provided to each of the one or more first transistors then each of the one or more first transistors substantially allows current to pass therethrough, and when the switching potential is not provided to each of the one or more first transistors then each of the one or more first transistors substantially prevents current from passing therethrough. 
     
     
       7. The circuitry according to  claim 1 , wherein each of the one or more first transistors is a field effect transistor. 
     
     
       8. The circuitry according to  claim 7 , wherein each of the one or more first transistors comprises a source, a drain, and a gate, and wherein in use the switching potential is provided to the gate of each of the one or more first transistors. 
     
     
       9. The circuitry according to  claim 1 , wherein each of the one or more first transistors is an n-channel field effect transistor. 
     
     
       10. The circuitry according to  claim 1 , wherein each of the one or more first transistors is a metal-oxide-semiconductor field effect transistor. 
     
     
       11. The circuitry according to  claim 1 , wherein the circuitry comprises a supply bus for supplying the switching potential from the converter to the plurality of driving arrangements in use. 
     
     
       12. The circuitry according to  claim 11 , wherein the supply bus is controllable to supply the switching potential to one or more of the plurality of driving arrangements in use. 
     
     
       13. The circuitry according to  claim 11 , wherein the circuitry comprises a supply bus controller arranged to control the supply bus to supply the switching potential to a selectable one or more of the plurality of driving arrangements in use. 
     
     
       14. The circuitry according to  claim 1 , wherein each of the plurality of driving arrangements comprises a driver controller arranged to control supply of the switching potential to the one or more first transistors of the driving arrangement. 
     
     
       15. The circuitry according to  claim 1 , wherein each of the plurality of driver arrangements is arranged for common connection to a DC power source to provide the input direct current in use. 
     
     
       16. The circuitry according to  claim 1 , wherein the converter is arranged for connection to a DC power source to provide the input potential in use. 
     
     
       17. The circuitry according to  claim 1 , wherein the converter is or comprises a boost converter. 
     
     
       18. An aerosol generating device comprising:
 the circuitry according to  claim 1 . 
 
     
     
       19. The aerosol generating device according to  claim 18 , the aerosol generating device further comprising:
 a DC power source, the DC power source being arranged to provide, in use, at least one of the input direct current or the input potential. 
 
     
     
       20. The aerosol generating device according to  claim 18 , the aerosol generating device further comprising:
 the plurality of induction elements, 
 wherein each of the plurality of driver arrangements is arranged to provide alternating current to a respective one of the plurality of induction elements in use. 
 
     
     
       21. The aerosol generating device according to  claim 20 , the aerosol generating device further comprising:
 the one or more susceptors, wherein the one or more susceptors are arranged to be inductively heated by the plurality of induction elements in use. 
 
     
     
       22. The aerosol generating device according to  claim 21 , wherein the aerosol generating device further comprises:
 the aerosol generating material, wherein the aerosol generating material is arranged to be heated by the one or more susceptors in use. 
 
     
     
       23. The aerosol generating device according to  claim 22 , wherein the aerosol generating material is or comprises tobacco.